package com.share.module.sys.user.listener;

import com.alibaba.excel.context.AnalysisContext;
import com.alibaba.excel.read.listener.ReadListener;
import com.alibaba.excel.util.ListUtils;
import com.alibaba.fastjson.JSON;
import com.share.module.sys.user.entity.User;
import com.share.module.sys.user.service.UserService;
import com.share.module.sys.user.vo.UploadUserVO;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeanUtils;
import java.util.List;

@Slf4j
public class UploadUserDataListener implements ReadListener<UploadUserVO> {

    /**
     * 每隔5条存储数据库，实际使用中可以100条，然后清理list ，方便内存回收
     */
    private static final int BATCH_COUNT = 100;
    private List<User> cachedDataList = ListUtils.newArrayListWithExpectedSize(BATCH_COUNT);

    private UserService userService;

    public UploadUserDataListener() {
    }

    public UploadUserDataListener(UserService userService) {
        this.userService = userService;
    }

    @Override
    public void invoke(UploadUserVO data, AnalysisContext analysisContext) {
        log.info("解析到一条数据:{}", JSON.toJSONString(data));
        User user = new User();
        BeanUtils.copyProperties(data, user);
        cachedDataList.add(user);
        // 达到BATCH_COUNT了，需要去存储一次数据库，防止数据几万条数据在内存，容易OOM
        if (cachedDataList.size() >= BATCH_COUNT) {
            saveData();
            // 存储完成清理 list
            cachedDataList = ListUtils.newArrayListWithExpectedSize(BATCH_COUNT);
        }
    }

    private void saveData() {
        log.info("{}条数据，开始存储数据库！", cachedDataList.size());
        userService.saveBatch(cachedDataList);
        log.info("存储数据库成功！");
    }

    @Override
    public void doAfterAllAnalysed(AnalysisContext analysisContext) {
        // 这里也要保存数据，确保最后遗留的数据也存储到数据库
        saveData();
        log.info("所有数据解析完成！");
    }
}
